1. Field of the Invention
This invention relates to an apparatus for controlling a device equipped on a vehicle and, more particularly, to an apparatus which easily executes appropriate device control when environmental conditions and regulatory requirements change depending on locations or time.
2. Description of the Related Art
As vehicle electronic control technology progresses, more and more on-vehicle devices are controlled by control apparatus comprising built-in computers. Control apparatuses designed specifically for each on-vehicle device as well as those which perform integrated control for a plurality of on-vehicle devices are commonly provided. Such control apparatuses store a control program specific to an on-vehicle device that control in a program memory and control the on-vehicle device according to the control program.
Such an on-vehicle device may be arbitrary device operated by computer control such as, for example, a combustion engine, an electric motor, a navigation unit, or an air conditioner.
Motor vehicles typically drive over wide and varying regions during the course of user operation and face circumstances that vary according to the region in which it operates. Even if operating in a single region, the surrounding circumstances will change according to time of day or season of the year. To be more specific, climatic (weather) and road conditions will change. It is also possible that region-by-region requirements for vehicles (such as regulatory requirements imposed on a vehicle) will vary according to location or time.
A control apparatus for an on-vehicle device must perform adequate control under all operating circumstances. In Japanese Patent Laid-Open Publication No. Hei 5-180023, for example, motor output control corresponding to a driving location is suggested. This art attempts to respond to the need only with a method of improving a control program to support a change in circumstances. Although this approach does allow device performance to improve, it has serious disadvantages including those of increasing the complexity of the program itself and of its control processes, increasing the size of the program, requiring larger storage capacity for the larger programs, and increasing costs by requiring, for example, the addition of new sensors.
With the current state of the art, a large number of device control apparatuses are not able to respond to changes in environmental conditions and even fewer are able to deal with changed regulatory requirements. For example, while a motor control program may use temperature or a similar environmental condition as a parameter to execute control appropriate to that environment, and attempt, as a goal, to produce greater power while reducing the level of emissions, configuring such a program to responds various environments with attention to all details causes the size of the program to increase as its complexity increases. Furthermore, the complexity and the size of such a program will expand as it is improved to support regulatory requirements.
Some on-vehicle device control apparatuses are equipped with a known control program designed for use in cold climates that warms a battery using a heater. This is a control program specific to a certain region. Programs of this nature are only used under particular circumstances. To equip a seldom used program is profitless and has disadvantages in terms of storage capacity.
Referring now to a hybrid car a well known vehicle type equipped both a combustion engine and an electric motor, as an example, the mode selection of a usage pattern of an engine and an electric motor allows reducing noise and the amount of emission gas, and allows enhancing motion performance by producing higher power. This can simultaneously fulfill the two conflicting criterion of low noise and high performance. Therefore, a hybrid car is expected to be one which could change its performance in order to fit environmental conditions and regulatory requirements. For instance, such a vehicle may drive mainly using the electric motor individually as a motor when it drives in a region where rigorous anti-noise regulations are established. In order to exploit such advantages, however, the conventional control apparatus needs to collect information about environmental conditions and regulatory requirements and must include a control program which can utilize the gathered information and, when regulatory requirements are changed, the control program should be updated. This is very difficult and, considering such difficult circumstances, an easier means to exploit the full potential of a hybrid car is greatly desired.
As mentioned above, known approaches include improving a control program or adding a special program for the purpose of the control supporting changes in circumstances such as environmental conditions and regulatory requirements. This approach has many disadvantages as were outlined above.